Effects of hydroxychloroquine on retinal vessel density in patients with rheumatoid arthritis over one-year follow-up: A pilot study

Background: To employ optical coherence tomography angiography (OCTA) to evaluate the effects of hydroxychloroquine (HCQ) on the superficial capillary plexus (SCP) and deep retinal capillary plexus (DCP) in patients affected by rheumatoid arthritis (RA). Methods: Patients with recent diagnosis of “definite RA”, based on 2010 Rheumatoid Arthritis Classification Criteria, were included in a prospective, observational imaging study carried out by the G.B. Bietti Foundation between March 2019 and January 2020. Vessel density (VD) of SCP and DCP, central foveal thickness (CFT) and foveal avascular zone (FAZ) values were collected by OCTA. The primary outcome measure was the VD alteration of SCP and DCP in RA-patients after one year of HCQ treatment. Results: OCTA data analysis showed no statistically significant reduction in the mean VD of SCP and DCP, including the mean global area, central subfield, inner ring and temporal, superior, nasal, and inferior sectors, as well as in the mean CFT and FAZ areas. Conclusions: OCTA demonstrated no early change in the VD in the SCP and DCP, in RA-patients after one year of HCQ treatment. A longer monitoring period would more precisely establish the treatment’s effect on the VD and its correlation with HCQ toxicity.